In general, the microwave oven cooks food, not by a method identical to a gas oven range that cooks the food by burning gas, but by elevating an inside temperature with electricity or directing a microwave to the food.
Since the microwave oven has no flame, and no hazard of gas leakage, with a less risk for causing accidents coming from negligence of safety compared to the gas oven range, the microwave oven has good response from consumers.
FIG. 1 illustrates a disassembled perspective view of a related art microwave oven, and FIG. 2 illustrates a plan view of a related art microwave oven, schematically.
Referring to FIGS. 1 and 2, the related art microwave oven is provided with a base plate 10, an outer case 12, a front plate 11 and a rear plate 13 at front and rear edges of the base plate 10 respectively, an inner case 20 between the front and rear plates 11 and 13, and an outfit chamber 40 for fitting various components.
The inner case 20 has a cooking chamber 20a therein, and the front plate 11 has a door 14 thereon for opening/closing the cooking chamber 20a. The outer case 12 covers the inner case 20 and the outfit chamber 40, for protecting the inner case 20 and the outfit chamber 40, together with the front and rear plates 11, and 13.
The rear plate 13 has a plurality of holes 13a in a central part in communication with the cooking chamber 20a inside of the inner case 20. There is a convection cover 31 mounted on the rear plate 13 to form a convection chamber therein.
In the convection cover 31, there are a heater 32, and a convection fan 34 for blowing air heated by the heater 32 to the cooking chamber 20a through the holes 13a in the rear plate 13.
There is a convection motor 35 in rear of the convection chamber for driving the convection fan 34. The convection motor 35 has a shaft 35a passed through the convection cover 31, and fixed to the convection fan 34.
In the meantime, there is an anti-fan 36 between the convection motor 35 and the convection fan 34, for cooling the convection motor 35. The anti-fan 36 leads an external air to pass through the convection motor 35, and be discharged through a side.
There is a chamber cover 37 in rear of the convection motor 35. The chamber cover 37 covers the convection cover 31 and the convection motor 35, and mounted on the rear plate 13.
FIG. 3 illustrates a back view of a related art microwave oven.
Referring to FIG. 3, the chamber cover 37 has a plurality of air inlet holes 37a in a central part for inlet of an external air, and air outlet holes 37b in one side part for outlet of the external air passed through the convection motor 35 by the anti-fan 36.
In the meantime, in the outfit chamber 40, there are a magnetron 41 for generating a microwave, a transformer 42 for supplying a high voltage to the magnetron 41, and a fan 43 for introduction of external air into the outfit chamber 40.
The fan 43 is fixed to a fan motor 44 mounted on the rear plate 13, and driven by the fan motor 44, for introducing the external air into the outfit chamber 40 to cool components, such as the magnetron 41, and the transformer 42 which generate heat during operation.
However, the related art microwave oven has the following problems.
First, the thickness of the convection cover 31 and the chamber cover 37 mounted on the rear plate 13 increases an overall size of the related art microwave oven, to cause difficulty in installation, and required much space.
Second, the hexahedral inner case 20, and the cooking chamber 20a formed therein cause difficulty in cleaning corner parts of the cooking chamber 20a, and concentration of the microwave on the corner parts, that impedes uniform heating of food.
Third, the provision of a separate anti-fan for cooling the convection motor 35 increases production cost, and requires an extra mounting process.